Non-Hermiticity Induced Flat Band

Abstract

We demonstrate the emergence of an entire flat band embedded in dispersive bands at the exceptional point of a PT symmetric photonic lattice. For this to occur, the gain and loss parameter effectively alters the size of the partial flat band windows and band gap of the photonic lattice simultaneously. The mode associated with the entire flat band is robust against changes in the system size and survives even at the edge of the lattice. Our proposal offers a route for controllable localization of light in non-Hermitian systems and a technique for measuring non-Hermiticity via localization.

References in corpus (8)

• Making Sense of Non-Hermitian Hamiltonians
• High temperature fractional quantum Hall states
• Fractional quantum Hall states at zero magnetic field
• Observation of a localized flat-band state in a photonic Lieb lattice
• Observation of bound states in Lieb photonic lattices
• Topological flat band models with arbitrary Chern numbers
• PT-Symmetric Talbot Effects
• Light transport in PT-invariant photonic structures with hidden symmetries

Cited by in corpus (36)

• Artificial flat band systems: from lattice models to experiments
• Non-Bloch band collapse and chiral Zener tunneling
• Defect states emerging from a non-Hermitian flat band of photonic zero modes
• Flat bands in lattices with non-Hermitian coupling
• Compact localized states and flat bands from local symmetry partitioning
• Experimental realisation of $\mathcal{P}\mathcal{T}$-symmetric flat bands
• Non-Hermitian lattices with a flat band and polynomial power increase
• Hybrid exceptional point created from type III Dirac point
• Flat band in two-dimensional non-Hermitian optical lattices
• Photonic Flatband Laser
• Fractal-like photonic lattices and localized states arising from singular and nonsingular flatbands
• Higher-order exceptional point and Landau-Zener Bloch oscillations in driven non-Hermitian photonic Lieb lattices
• Flat band induced by the interplay of synthetic magnetic flux and non-Hermiticity
• Geometry and superfluidity of the flat band in a non-Hermitian optical lattice
• Controllable unidirectional transport and photon storage in an one-dimensional lattice with complex hopping rates
• Robust localized zero-energy modes from locally embedded PT-symmetric defects
• Non-Hermitian flatband generator in one dimension
• Flat bands and compactons in mechanical lattices
• Interplay of quantum phase transition and flat band in hybrid lattices
• Floquet control of global $PT$ symmetry in 2D arrays of quadrimer waveguides
• Localization-Delocalization Transitions in Non-Hermitian Aharonov-Bohm Cages
• Stable Bloch oscillations and Landau-Zener tunneling in a non-Hermitian $\mathcal{P}\mathcal{T}$-symmetric flat band lattice
• Non-singular and singular flat bands in tunable acoustic metamaterials
• Dissipation Induced Flat Bands
• Generalized Lieb's theorem for noninteracting non-Hermitian $n$-partite tight-binding lattices
• Tunable Aharonov-Bohm cages through anti-$\mathcal{P}\mathcal{T}$-symmetric imaginary couplings
• Robust incoherent perfect absorption
• Non-diffracting states at exceptional points
• Spectral Singularities with Directional Sensitivity
• The Effect of non-Hermiticity on Adiabatic Elimination
• Fate of localization features in a one-dimensional non-Hermitian flat-band lattice with quasiperiodic modulations
• Non-Local Elastic Lattices with $\mathcal{P}\mathcal{T}$-Symmetry and Time Modulation: From Perfect Trapping to the Wave Boomerang Effect
• Analytic approximation for eigenvalues of a class of $\mathcal{P}\mathcal{T}$ symmetric Hamiltonians
• Non-Hermitian Aharonov-Bohm Cage
• Exceptional flat bands in bipartite non-Hermitian lattices
• Extra Loss-free Non-Hermitian Engineered Single Mode Laser Systems